Projection screen light field display gain method and system for ambient light

Abstract

The present application relates to the technical field of projection display, and discloses a method and system for projection screen light field display gain under ambient light. The method establishes a dynamic light field distribution model through real-time acquisition of ambient light data, projection screen data and projection device original output signal, and fusion processing. Based on the dynamic light field distribution model, adaptive genetic algorithm is used to optimize compensation weight, and a light field compensation parameter set is generated to perform reverse compensation processing on the original output signal in terms of brightness gain, contrast and chrominance offset, and generate an enhanced projection signal. The system includes multi-source data acquisition, light field feature extraction, dynamic compensation calculation, signal enhancement processing and closed-loop feedback control modules, ensures that the projection image maintains the best display effect under different ambient light conditions, and significantly improves the audience viewing experience.

Description

Technical Field

[0001] This invention relates to the field of projection display technology, and more specifically to a method and system for increasing the light field display gain of a projection screen under ambient light. Background Technology

[0002] In stereoscopic projection display technology, the stereoscopic image output by the projection device is often significantly affected by ambient light. Especially in environments with complex and variable lighting, ambient light not only reduces the brightness of the projected image but also weakens its contrast and causes color shifts, thus affecting the viewing experience of the stereoscopic display. Although traditional stereoscopic projection display technologies consider the influence of ambient light to some extent, they mostly use fixed compensation methods, which are difficult to adapt to dynamic changes under different ambient light conditions. Especially in stereoscopic display applications that require high realism and immersion, such as cinemas, exhibitions, and virtual reality experiences, the interference of ambient light is particularly prominent, urgently requiring a solution that can adapt to changes in ambient light in real time and effectively improve the stereoscopic display effect. Summary of the Invention

[0003] To address the aforementioned technical shortcomings, the purpose of this invention is to provide a method and system for increasing the light field display gain of a projection screen under ambient light, thereby solving the problems of reduced brightness, weakened contrast, and color shift in existing stereoscopic projection displays due to the susceptibility of ambient light to these effects.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] In a first aspect, the present invention provides a method for displaying light field gain of a projection screen under ambient light, the method comprising:

[0006] Real-time acquisition of ambient light data, projection screen data, and raw output signals of the projection device. Ambient light data includes spectral distribution data, light intensity distribution data, and incident angle data. Projection screen data includes real-time reflectivity parameters and scattering characteristic parameters.

[0007] Ambient light data and projection screen data are fused together. Ambient light noise interference is eliminated by temporal filtering and spatial correction. The superimposed light field characteristics formed by ambient light on the projection screen surface are extracted, and a dynamic light field distribution model is established.

[0008] The compensation value is iteratively calculated based on the dynamic light field distribution model. A three-dimensional compensation matrix containing incident light attenuation coefficient, scattering compensation factor and reflection enhancement parameter is constructed. The compensation weight is optimized by an adaptive genetic algorithm to generate a set of light field compensation parameters for the current ambient light scene.

[0009] The original output signal is subjected to inverse compensation processing based on the light field compensation parameter set, and the brightness gain, contrast and chromaticity offset of the output signal are adjusted to generate an enhanced projection signal that is negatively correlated with ambient light interference.

[0010] The projection equipment outputs an enhanced projection signal, and at the same time establishes a closed-loop feedback mechanism to monitor the compensation effect in real time and periodically update the compensation parameters.

[0011] Preferably, in one possible implementation of the first aspect, the process of fusing ambient light data and projection screen data includes:

[0012] A sliding window mean filter is used to smooth the light intensity distribution data in the time domain, and a Gaussian spatial filter is used to eliminate high-frequency noise.

[0013] The real-time reflectivity parameters of the projection screen are dynamically calibrated, and the superimposed light field characteristics of ambient light and projection light are separated by a multi-scale decomposition algorithm.

[0014] The distribution of scattering characteristics on the surface of the curtain is identified based on the region growing algorithm, and a light field propagation path model is established by combining the incident angle data.

[0015] By mapping the light intensity, incident angle, and reflectivity parameters to a three-dimensional grid coordinate system, a dynamic light field distribution model containing spatiotemporal correlations is generated.

[0016] Preferably, in one possible implementation of the first aspect, the calculation formula for the dynamic light field distribution model is:

[0017]

[0018] in, For position Place The light intensity on the surface of the curtain of time. For position The reflection characteristic parameters, and Positions Place Ambient light and projected light intensity over time Let be the incident angle of the ambient light. For position Scattering characteristic parameters at that location.

[0019] Preferably, in one possible implementation of the first aspect, the iterative calculation process of the compensation value includes:

[0020] The incident light attenuation coefficient is calculated based on the spatiotemporal distribution difference between ambient light and projection light. The scattering compensation factor is obtained by multi-dimensional interpolation based on the scattering characteristic parameters of the screen surface. At the same time, the reflection enhancement parameter is generated by dynamic calibration through reflectivity parameter.

[0021] Construct a three-dimensional compensation matrix that includes the incident light attenuation coefficient, scattering compensation factor, and reflection enhancement parameters;

[0022] An adaptive genetic algorithm is used to optimize the compensation weights, thereby achieving global optimization in the parameter space, and the three-dimensional compensation matrix is ​​iteratively optimized layer by layer.

[0023] Finally, a light field compensation parameter set containing multi-dimensional compensation parameters is generated based on the spatial distribution characteristics of the current ambient light scene.

[0024] Preferably, in one possible implementation of the first aspect, the calculation of the incident light attenuation coefficient satisfies the following relationship:

[0025]

[0026] in, 3D mesh points The incident light attenuation coefficient at that point 3D mesh points Place Ambient light intensity over time 3D mesh points Place The intensity of projected light over time To prevent division by zero constant, to For sampling time window;

[0027] The calculation process for the scattering compensation factor is as follows:

[0028]

[0029] in, 3D mesh points The scattering compensation factor at that location. The intrinsic scattering coefficient of the curtain material is... 3D mesh points Scattering parameters at that location, This is a scattering intensity adjustment factor. The squared L2 norm of ambient light intensity;

[0030] The reflection enhancement parameters satisfy:

[0031]

[0032] in, 3D mesh points The reflection enhancement parameters at that location, For the surface of the screen The reflectivity of the target at that location This is the reflectivity adjustment coefficient.

[0033] Preferably, in one possible implementation of the first aspect, the objective function of the adaptive genetic algorithm is:

[0034]

[0035] in, The weight matrix is ​​determined by the optical characteristics of the projection device. To compensate for the parameter set, For the target light intensity distribution, The Laplacian smoothing operator is generated based on the topological structure of the curtain surface. The penalty coefficient is... for The transpose of .

[0036] Preferably, in one possible implementation of the first aspect, the reverse compensation process includes:

[0037] The output signal brightness gain is adjusted pixel by pixel based on the incident light attenuation coefficient, the high-frequency components of the image are contrast compensated according to the scattering compensation factor, and the color gamut boundary of the projection signal is dynamically expanded by combining the reflection enhancement parameter.

[0038] The chromaticity shift is calculated by utilizing the synergistic effect of the scattering compensation factor and the reflection enhancement parameter, and the color space coordinates of the projected signal are nonlinearly corrected.

[0039] Finally, the image data after brightness gain adjustment, contrast compensation, and color correction is subjected to multi-channel fusion processing to generate an enhanced projection signal that is negatively correlated with ambient light interference.

[0040] Preferably, in one possible implementation of the first aspect, the adjustment formula for the chromaticity offset is:

[0041]

[0042] in, Represents three-dimensional mesh points The chromaticity offset at that location. For color adjustment factor, and These are the scattering compensation factor and reflection enhancement parameter for the corresponding grid points, respectively. It is a non-linear adjustment index. The L2 norm represents the ambient light intensity.

[0043] Preferably, in one possible implementation of the first aspect, the implementation of the closed-loop feedback mechanism includes:

[0044] After the projection signal is output, the actual display effect data of the screen surface is collected in real time by the light sensor;

[0045] Calculate the peak signal-to-noise ratio and chromaticity difference of the compensated image. If the peak signal-to-noise ratio is lower than the threshold or the chromaticity difference exceeds the tolerance, the parameter update is triggered.

[0046] The light field distribution modeling and light field compensation calculations are periodically re-executed.

[0047] In a second aspect, the present invention provides a projection screen light field display gain system for ambient light conditions, the system comprising:

[0048] The multi-source data acquisition module is used to acquire ambient light data, projection screen data and the raw output signal of the projection device in real time. Ambient light data includes spectral distribution data, light intensity distribution data and incident angle data. Projection screen data includes real-time reflectivity parameters and scattering characteristic parameters.

[0049] The light field feature extraction module is used to fuse ambient light data and projection screen data. It eliminates ambient light noise interference through temporal filtering and spatial correction, extracts the superimposed light field features formed by ambient light on the projection screen surface, and establishes a dynamic light field distribution model.

[0050] The dynamic compensation calculation module performs iterative calculation of compensation values ​​based on the dynamic light field distribution model, constructs a three-dimensional compensation matrix that includes incident light attenuation coefficient, scattering compensation factor and reflection enhancement parameters, optimizes the compensation weights through an adaptive genetic algorithm, and generates a set of light field compensation parameters for the current ambient light scene.

[0051] The signal enhancement processing module performs reverse compensation processing on the original output signal according to the light field compensation parameter set, adjusts the brightness gain, contrast and chromaticity offset of the output signal, and generates an enhanced projection signal that is negatively correlated with ambient light interference.

[0052] The closed-loop feedback control module is used to output enhanced projection signals from the projection device, while establishing a closed-loop feedback mechanism to monitor the compensation effect in real time and periodically update the compensation parameters.

[0053] The beneficial effects of this invention are as follows: By real-time acquisition of ambient light data, projection screen data, and the original output signal of the projection device, and performing fusion processing, a dynamic light field distribution model is established. Based on this model, an adaptive genetic algorithm is used to optimize the compensation weights, generate a light field compensation parameter set for the current ambient light scene, and perform inverse compensation processing on the original output signal for brightness gain, contrast, and chromaticity shift, thereby generating an enhanced projection signal.

[0054] This invention not only significantly improves the brightness gain and contrast of stereoscopic projection displays, but also accurately corrects chromaticity shifts, ensuring optimal display performance of stereoscopic images under various ambient light conditions. Furthermore, the closed-loop feedback mechanism established in this invention monitors the compensation effect in real time and periodically updates the compensation parameters, further enhancing the stability and adaptability of stereoscopic displays and providing viewers with a more realistic and immersive stereoscopic viewing experience. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This application provides a flowchart of a method for increasing the light field display gain of a projection screen under ambient light.

[0057] Figure 2 This application provides a structural diagram of a projection screen light field display gain system for ambient light conditions.

[0058] Explanation of reference numerals in the attached diagram: 1-Multi-source data acquisition module, 2-Optical field feature extraction module, 3-Dynamic compensation calculation module, 4-Signal enhancement processing module, 5-Closed-loop feedback control module. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] Example 1: As Figure 1 As shown, the present invention provides a method for increasing the light field display gain of a projection screen under ambient light, comprising:

[0061] Real-time acquisition of ambient light data, projection screen data, and the raw output signal of the projection device. Ambient light data includes spectral distribution data, light intensity distribution data, and incident angle data. Projection screen data includes real-time reflectivity parameters and scattering characteristic parameters.

[0062] In this embodiment, ambient light data is acquired through a distributed multispectral sensor array deployed around the projection screen. This array consists of a high-precision light intensity sensor, a narrowband spectral analysis module, and a wide-angle optical lens, simultaneously acquiring ambient light spectral distribution data, dynamic light intensity distribution data, and incident angle data at various locations on the projection screen surface. Specifically, the spectral distribution data is obtained by using the narrowband spectral analysis module to perform 16-channel discrete sampling of the 400-700nm visible light band, generating a normalized spectral energy distribution histogram. The light intensity distribution data is obtained through a photosensitive element array combined with an adaptive integrator circuit, achieving linear measurement over a wide dynamic range of 0.01 lux to 100,000 lux. The incident angle data is obtained by using a wide-angle optical lens combined with a light spot deformation analysis algorithm to calculate the azimuth and elevation angles of the ambient light source, achieving an angular resolution of 0.1°.

[0063] The acquisition of projection screen data is achieved through a miniature reflectivity sensor and scattering characteristic detection device embedded in the screen substrate. The real-time reflectivity parameter is dynamically measured using pulsed laser ranging combined with the reflected light intensity ratio method. By periodically emitting 905nm near-infrared laser pulses on the screen surface and receiving their diffuse reflection signals, the real-time reflectivity parameters of each area are calculated according to the Lambertian reflection model, with a measurement frequency of 60Hz. The scattering characteristic parameters are obtained through a built-in miniature grating array combined with the Mie scattering theory inversion algorithm. The scattering phase function of the microstructure of the screen surface is fitted using multi-angle scattered light intensity distribution data, and the wavelength-related scattering anisotropy factor is extracted.

[0064] The original output signal of the projection device is acquired in real time through the data capture module of the HDMI / SDI interface. The brightness, contrast and RGB color gamut coordinates of the original video stream are analyzed by the FPGA hardware decoder, and the video stream frame data is aligned with the ambient light and screen data by the timestamp synchronization mechanism.

[0065] Ambient light data and projection screen data are fused together. Ambient light noise interference is eliminated through temporal filtering and spatial correction. The superimposed light field characteristics formed by ambient light on the projection screen surface are extracted, and a dynamic light field distribution model is established.

[0066] In this embodiment, the light intensity distribution data is first smoothed in the temporal domain. A sliding window mean filter with a window length of 5 frames is used to calculate a moving average of the temporal light intensity data to eliminate impulse noise caused by instantaneous strong light interference. Then, the standard deviation is combined with... A Gaussian spatial filter performs spatial convolution operations on the light intensity data, using a three-dimensional Gaussian kernel function. Suppress high-frequency noise components in space and improve the signal-to-noise ratio of light intensity data.

[0067] When dynamically calibrating the real-time reflectivity parameters of the projection screen, a three-level wavelet decomposition of the superimposed light field is performed using the Haar wavelet basis to separate the characteristic components of ambient light and projection light in the frequency domain. Specifically, the steady-state component of ambient light is reconstructed using low-frequency subband coefficients, and the dynamic details of projection light are extracted using high-frequency subband coefficients. Simultaneously, a region growing algorithm is used to perform spatial clustering analysis on the scattering characteristics of the screen surface: regions with a scattering parameter standard deviation less than 0.05 are used as seed points, and adjacent grids with similar scattering characteristics are gradually merged using an eight-neighbor expansion strategy, ultimately forming a partitioned topology map containing anisotropic scattering characteristics.

[0068] In the light field propagation path modeling stage, the incident angle The parameters are geometrically projected onto the screen surface normal vector, and a ray tracing algorithm is used to simulate the reflection path of ambient light on the screen surface, generating a dynamic light field distribution model.

[0069]

[0070] in, For position Place The light intensity on the surface of the curtain of time. For position The reflection characteristic parameters, and Positions Place Ambient light and projected light intensity over time are obtained from adjacent sensor data using a bilinear interpolation algorithm. Let be the incident angle of the ambient light. For position The model uses a dynamic update mechanism to refresh the parameters every 50ms, characterizing the nonlinear superposition effect of ambient light and projection light on the screen surface.

[0071] The compensation value is iteratively calculated based on the dynamic light field distribution model. A three-dimensional compensation matrix containing incident light attenuation coefficient, scattering compensation factor and reflection enhancement parameter is constructed. The compensation weight is optimized by an adaptive genetic algorithm to generate a set of light field compensation parameters for the current ambient light scene.

[0072] In this embodiment, the iterative calculation process of the compensation value is based on the spatiotemporal correlation data output by the dynamic light field distribution model. First, the incident light attenuation coefficient is calculated based on the spatiotemporal distribution differences between ambient light and projected light, specifically through the light intensity ratio relationship of each spatiotemporal node in the three-dimensional grid coordinate system. For each three-dimensional grid point... Its incident light attenuation coefficient The calculation satisfies the following relationship:

[0073]

[0074] in, 3D mesh points The incident light attenuation coefficient at that point 3D mesh points Place Ambient light intensity over time 3D mesh points Place The intensity of projected light over time To prevent division by zero constant, to This refers to the sampling time window. (Time window) Set to a sliding sampling period of the most recent 100ms, ambient light intensity With projected light intensity Obtained through the bilinear interpolation module in the dynamic light field distribution model. (Zero constant is excluded.) Set as This coefficient is used to avoid numerical instability caused by the denominator approaching zero. It characterizes the degree to which ambient light suppresses projected light; as the proportion of ambient light intensity increases, When the value approaches 0, it triggers a higher intensity of brightness compensation demand.

[0075] The calculation process for the scattering compensation factor integrates the intrinsic properties of the curtain material with dynamic measurement data. For each grid point... Scattering compensation factor Generated through an exponential decay function:

[0076]

[0077] in, 3D mesh points The scattering compensation factor at that location. The intrinsic scattering coefficient of the screen material is... 3D mesh points Scattering parameters at that location, This is a scattering intensity adjustment factor. The L2 norm squared represents the ambient light intensity, and the intrinsic scattering coefficient of the screen is... The scattering parameter is preset to 0.82 using a material spectral database. The scattering intensity is adjusted in real time by a built-in micro-grating array. The value is adaptively adjusted to a dynamic value within the range of 0.75-1.25 based on the topology of the curtain surface. The L2 norm squared term in the formula... The scattering compensation factor is obtained by calculating the square of the magnitude of the intensity vector of ambient light in the RGB three channels, which enables the scattering compensation factor to effectively suppress the composite interference of multispectral ambient light.

[0078] Reflection enhancement parameters The calculation uses the hyperbolic tangent function to achieve nonlinear adjustment, and its expression is:

[0079]

[0080] Among them, target reflectivity The reflectivity adjustment coefficient is set to 0.95 based on the ideal reflectivity characteristics of the curtain material. The value was calibrated to 0.3 through experiments. When the ambient light intensity exceeds the projected light intensity, The function output value approaches This makes the reflection enhancement parameter Reaching the theoretical maximum value When the projected light is dominant, the output value approaches... The parameter value dropped to This enables dynamic bidirectional adjustment of reflection characteristics.

[0081] After completing the calculation of each compensation parameter, the system construction includes , , The three-dimensional compensation matrix maintains the same dimensions as the spatial resolution (1920×1080) and temporal sampling depth (10-frame buffer) of the dynamic light field distribution model. This matrix integrates three types of parameters into a unified data structure using tensor concatenation, with each grid point corresponding to a parameter vector containing 24-bit floating-point numbers.

[0082] The parameter optimization stage employs an improved adaptive genetic algorithm, whose objective function is defined as:

[0083]

[0084] in, The weight matrix is ​​determined by the optical characteristics of the projection device. To compensate for the parameter set, For the target light intensity distribution, The Laplacian smoothing operator is generated based on the topological structure of the curtain surface. The penalty coefficient is... for The transpose of the weight matrix. Determined by the optical modulation transfer function of the projection device, including the RGB channel gain coefficients for each pixel; compensation parameter set. Vectorized representation of the three-dimensional compensation matrix; target light intensity distribution Generated according to the international display metrology standard CIE 1931 colorimetric specification; Laplace smoothing operator. Constructed based on the curvature data of the curtain surface, its matrix elements The penalty coefficient is assigned based on the reciprocal of the geodesic distance between adjacent grid points. The signal-to-noise ratio is dynamically adjusted within the range of 0.1-10.

[0085] In the algorithm implementation, the initial population size is set to 200 individuals, and the genes of each individual consist of normalized values ​​of compensation parameters. Selection is performed using a tournament mechanism, selecting the top 20% of fittest individuals from each generation to enter the mating pool. The crossover probability is adaptively adjusted between 0.6 and 0.9 based on the population diversity index. Mutation employs a Gaussian perturbation strategy with a standard deviation of [missing value]. The value decreases linearly from 0.1 to 0.01 with each iteration. After each generation of evolution, the system performs layer-by-layer iterative optimization of the three-dimensional compensation matrix, that is, prioritizing the optimization of XY plane parameters in the spatial dimension, followed by temporal consistency correction along the time axis. When the objective function value changes by less than 0.01 for five consecutive generations... The algorithm terminates and outputs a set of light field compensation parameters when the maximum number of iterations (100) is reached. This parameter set is ultimately encapsulated into a binary data packet containing spatial coordinate mappings and timestamps, which is then used by the signal enhancement processing module.

[0086] The original output signal is inversely compensated based on the light field compensation parameter set, and the brightness gain, contrast and chromaticity offset of the output signal are adjusted to generate an enhanced projection signal that is negatively correlated with ambient light interference.

[0087] In this embodiment, the system first uses the incident light attenuation coefficient stored in the three-dimensional compensation matrix. The brightness gain of the original output signal is adjusted pixel-by-pixel. For each 3D grid point... ,based on The value is non-linearly mapped to the luminance components of the RGB channels, and a piecewise exponential function is used to achieve coordinated adjustment of dark area enhancement and highlight suppression. Specifically, the luminance gain adjustment range of dark area pixels varies with... The decrease in value increases logarithmically, while the adjustment slope in the highlight area is limited by the Sigmoid function to prevent overexposure.

[0088] During the contrast compensation stage, the system adjusts the scattering compensation factor accordingly. Dynamic enhancement of high-frequency components in an image is performed. The original image is decomposed into low-frequency and high-frequency sub-bands using a two-dimensional discrete wavelet transform, and enhancement is applied to the high-frequency detail components. The gain coefficient is positively correlated with the value. This gain coefficient satisfies... The nonlinear relationship, in which The calibrated adjustment index (typically 1.2-1.5) allows for differentiated contrast compensation in areas with significant differences in scattering characteristics. Simultaneously, this is combined with reflection enhancement parameters. The color gamut boundary of the projected signal is dynamically expanded by translating the RGB color gamut coordinates towards the edge of the CIE 1931 color space, with the expansion amount being... The product of the current color gamut coverage is dynamically determined to ensure that the wide color gamut display characteristics can still be maintained under ambient light interference.

[0089] The chromaticity shift is calculated using the scattering compensation factor. With reflection enhancement parameters The synergistic effect is achieved, and its adjustment formula is:

[0090]

[0091] in, Represents three-dimensional mesh points The chromaticity offset at that location. For color adjustment factor, and These are the scattering compensation factor and reflection enhancement parameter for the corresponding grid points, respectively. It is a non-linear adjustment index. The L2 norm represents the ambient light intensity. This refers to the colorimetric adjustment factor calibrated by the equipment (typical value 0.8-1.2). The nonlinear adjustment exponent (range 1.0-2.0) enhances the coupling effect of scattering and reflection characteristics on chromaticity correction through the exponential operation of the two-parameter product term, using the ambient light intensity L2 norm. Simultaneously, the intensity ratio of ambient light to projected light is introduced as a dynamic adjustment term, thus adjusting the chromaticity shift. It can adapt to ambient light interference intensity. The calculated chromaticity shift is applied to the CIELAB color space, and the original projection signal is transformed using a nonlinear transformation matrix. , The channel is translated to correct chromatic distortion caused by ambient light absorption.

[0092] After completing independent corrections for each dimension, the system employs multi-channel fusion technology to synthesize the processed brightness, contrast, and chromaticity data. During the fusion process, a weighted least squares algorithm is used to eliminate cross-interference between compensation dimensions, and the weight matrix is ​​dynamically adjusted based on the confidence level of the compensation parameters. The final enhanced projection signal is ensured to meet the physical limitations of the target display device through a color gamut clipping module and is output to the optical engine of the projection device with 12-bit quantization precision, forming a high-quality display image that is negatively correlated with ambient light interference.

[0093] The projection equipment outputs an enhanced projection signal, and at the same time establishes a closed-loop feedback mechanism to monitor the compensation effect in real time and periodically update the compensation parameters.

[0094] In this embodiment, a high-sensitivity photoelectric sensor array distributed along the edge of the projection screen is used to collect real-time data on the actual light field distribution of the compensated screen surface. The sensor array consists of a 16-bit analog-to-digital converter and a wide dynamic range photodiode, simultaneously capturing the brightness, chromaticity, and spectral characteristics of each spatial location at a sampling frequency of 200Hz. After preprocessing, the collected data is used to calculate the peak signal-to-noise ratio (PSNR) and chromaticity difference of the compensated image in parallel using the Structural Similarity Index (SSIM) and the CIEDE2000 color difference formula. The PSNR is dynamically evaluated by comparing the mean square error of the original projection signal and the feedback light field in the YUV color space, while the chromaticity difference is calculated using the CIE 1976 Labs. The Euclidean distance in the color space is calculated, while also taking into account the influence coefficient of ambient light on the sensitivity of specific wavelengths.

[0095] When the PSNR is detected to be lower than the preset 30dB or the color difference exceeds [a certain threshold], In case of an emergency, a three-level parameter update mechanism is automatically triggered: First, the temporal filtering window in the light field distribution model is dynamically shrunk, compressing the sampling period of the sliding window mean filter from 100ms to 50ms to improve response speed; then, a fast genetic algorithm is used to locally optimize the compensation parameter set, reducing the population size to 50 individuals and employing an elite retention strategy to accelerate convergence; finally, the optimized compensation parameters are injected into the signal processing pipeline through incremental updates to ensure a smooth transition of the projected image. For normal operating conditions where no alarm is triggered, the system establishes a periodic full-parameter update mechanism, re-executing the complete light field distribution modeling and compensation calculation process every 5 seconds. During the update process, double buffering technology is used to achieve atomic replacement of compensation parameters, avoiding image flickering or tearing.

[0096] Example 2: Figure 2 As shown, the present invention provides a projection screen light field display gain system for ambient light conditions, comprising:

[0097] The multi-source data acquisition module 1 is used to acquire ambient light data, projection screen data and the original output signal of the projection device in real time. The ambient light data includes spectral distribution data, light intensity distribution data and incident angle data. The projection screen data includes real-time reflectivity parameters and scattering characteristic parameters.

[0098] The light field feature extraction module 2 is used to fuse ambient light data and projection screen data, eliminate ambient light noise interference through temporal filtering and spatial correction, extract the superimposed light field features formed by ambient light on the projection screen surface, and establish a dynamic light field distribution model.

[0099] The dynamic compensation calculation module 3 performs iterative calculation of compensation values ​​based on the dynamic light field distribution model, constructs a three-dimensional compensation matrix including incident light attenuation coefficient, scattering compensation factor and reflection enhancement parameters, optimizes the compensation weights through an adaptive genetic algorithm, and generates a set of light field compensation parameters for the current ambient light scene.

[0100] The signal enhancement processing module 4 performs reverse compensation processing on the original output signal according to the light field compensation parameter set, adjusts the brightness gain, contrast and chromaticity offset of the output signal, and generates an enhanced projection signal that is negatively correlated with ambient light interference.

[0101] The closed-loop feedback control module 5 is used to output an enhanced projection signal from the projection device, and at the same time establishes a closed-loop feedback mechanism to monitor the compensation effect in real time and periodically update the compensation parameters.

[0102] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for increasing the light field display gain of a projection screen under ambient light, characterized in that, The method includes: Real-time acquisition of ambient light data, projection screen data, and raw output signals of the projection device. Ambient light data includes spectral distribution data, light intensity distribution data, and incident angle data. Projection screen data includes real-time reflectivity parameters and scattering characteristic parameters. Ambient light data and projection screen data are fused together. Ambient light noise interference is eliminated by temporal filtering and spatial correction. The superimposed light field characteristics formed by ambient light on the projection screen surface are extracted, and a dynamic light field distribution model is established. The compensation value is iteratively calculated based on the dynamic light field distribution model. A three-dimensional compensation matrix containing incident light attenuation coefficient, scattering compensation factor and reflection enhancement parameter is constructed. The compensation weight is optimized by an adaptive genetic algorithm to generate a set of light field compensation parameters for the current ambient light scene. The iterative calculation process for the compensation value includes: The incident light attenuation coefficient is calculated based on the spatiotemporal distribution difference between ambient light and projection light. The scattering compensation factor is obtained by multi-dimensional interpolation based on the scattering characteristic parameters of the screen surface. At the same time, the reflection enhancement parameter is generated by dynamic calibration through reflectivity parameter. Construct a three-dimensional compensation matrix that includes the incident light attenuation coefficient, scattering compensation factor, and reflection enhancement parameters; An adaptive genetic algorithm is used to optimize the compensation weights, thereby achieving global optimization in the parameter space, and the three-dimensional compensation matrix is ​​iteratively optimized layer by layer. Finally, a light field compensation parameter set containing multi-dimensional compensation parameters is generated based on the spatial distribution characteristics of the current ambient light scene; The calculation of the incident light attenuation coefficient satisfies the following relationship: in, 3D mesh points The incident light attenuation coefficient at that point 3D mesh points Place Ambient light intensity over time 3D mesh points Place The intensity of projected light over time To prevent division by zero constant, to For sampling time window; The calculation process for the scattering compensation factor is as follows: in, 3D mesh points The scattering compensation factor at that location. The intrinsic scattering coefficient of the curtain material is... 3D mesh points Scattering parameters at that location, This is a scattering intensity adjustment factor. The squared L2 norm of ambient light intensity; The reflection enhancement parameters satisfy: in, 3D mesh points The reflection enhancement parameters at that location, For the surface of the screen The reflectivity of the target at that location This is the reflectivity adjustment coefficient; The objective function of the adaptive genetic algorithm is: in, The weight matrix is ​​determined by the optical characteristics of the projection device. To compensate for the parameter set, For the target light intensity distribution, The Laplacian smoothing operator is generated based on the topological structure of the curtain surface. The penalty coefficient is... for Transpose of; The original output signal is subjected to inverse compensation processing based on the light field compensation parameter set, and the brightness gain, contrast and chromaticity offset of the output signal are adjusted to generate an enhanced projection signal that is negatively correlated with ambient light interference. The projection equipment outputs an enhanced projection signal, and at the same time establishes a closed-loop feedback mechanism to monitor the compensation effect in real time and periodically update the compensation parameters.

2. The method for increasing the light field display gain of a projection screen under ambient light as described in claim 1, characterized in that, The process of fusing ambient light data and projection screen data includes: A sliding window mean filter is used to smooth the light intensity distribution data in the time domain, and a Gaussian spatial filter is used to eliminate high-frequency noise. The real-time reflectivity parameters of the projection screen are dynamically calibrated, and the superimposed light field characteristics of ambient light and projection light are separated by a multi-scale decomposition algorithm. The distribution of scattering characteristics on the surface of the curtain is identified based on the region growing algorithm, and a light field propagation path model is established by combining the incident angle data. By mapping the light intensity, incident angle, and reflectivity parameters to a three-dimensional grid coordinate system, a dynamic light field distribution model containing spatiotemporal correlations is generated.

3. The method for increasing the light field display gain of a projection screen under ambient light as described in claim 2, characterized in that, The calculation formula for the dynamic light field distribution model is as follows: in, For position Place The light intensity on the surface of the curtain of time. For position The reflection characteristic parameters, and Positions Place Ambient light and projected light intensity over time Let be the incident angle of the ambient light. For position Scattering characteristic parameters at that location.

4. The method for increasing the light field display gain of a projection screen under ambient light as described in claim 1, characterized in that, The reverse compensation process includes: The output signal brightness gain is adjusted pixel by pixel based on the incident light attenuation coefficient, the high-frequency components of the image are contrast compensated according to the scattering compensation factor, and the color gamut boundary of the projection signal is dynamically expanded by combining the reflection enhancement parameter. The chromaticity shift is calculated by utilizing the synergistic effect of the scattering compensation factor and the reflection enhancement parameter, and the color space coordinates of the projected signal are nonlinearly corrected. Finally, the image data after brightness gain adjustment, contrast compensation, and color correction is subjected to multi-channel fusion processing to generate an enhanced projection signal that is negatively correlated with ambient light interference.

5. The method for increasing the light field display gain of a projection screen under ambient light as described in claim 4, characterized in that, The formula for adjusting the chromaticity offset is: in, Represents three-dimensional mesh points The chromaticity offset at that location. For color adjustment factor, and These are the scattering compensation factor and reflection enhancement parameter for the corresponding grid points, respectively. It is a non-linear adjustment index. The L2 norm represents the ambient light intensity.

6. The method for increasing the light field display gain of a projection screen under ambient light as described in claim 1, characterized in that, The implementation of the closed-loop feedback mechanism includes: After the projection signal is output, the actual display effect data of the screen surface is collected in real time by the light sensor; Calculate the peak signal-to-noise ratio and chromaticity difference of the compensated image. If the peak signal-to-noise ratio is lower than the threshold or the chromaticity difference exceeds the tolerance, the parameter update is triggered. The light field distribution modeling and light field compensation calculations are periodically re-executed.

7. A projection screen light field display gain system for use under ambient light, characterized in that, The system is implemented based on the projection screen light field display gain method for ambient light as described in any one of claims 1 to 6, comprising: The multi-source data acquisition module is used to acquire ambient light data, projection screen data and the raw output signal of the projection device in real time. Ambient light data includes spectral distribution data, light intensity distribution data and incident angle data. Projection screen data includes real-time reflectivity parameters and scattering characteristic parameters. The light field feature extraction module is used to fuse ambient light data and projection screen data. It eliminates ambient light noise interference through temporal filtering and spatial correction, extracts the superimposed light field features formed by ambient light on the projection screen surface, and establishes a dynamic light field distribution model. The dynamic compensation calculation module performs iterative calculation of compensation values ​​based on the dynamic light field distribution model, constructs a three-dimensional compensation matrix that includes incident light attenuation coefficient, scattering compensation factor and reflection enhancement parameters, optimizes the compensation weights through an adaptive genetic algorithm, and generates a set of light field compensation parameters for the current ambient light scene. The signal enhancement processing module performs reverse compensation processing on the original output signal according to the light field compensation parameter set, adjusts the brightness gain, contrast and chromaticity offset of the output signal, and generates an enhanced projection signal that is negatively correlated with ambient light interference. The closed-loop feedback control module is used to output enhanced projection signals from the projection device, while establishing a closed-loop feedback mechanism to monitor the compensation effect in real time and periodically update the compensation parameters.

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